Improved marine propeller



- UNITED STATES PATENT OFFICE.

BENJAMIN T. EABBITT, or NEW YORK, N. Y.

IM PROVED MARINE PROPELLER.

Specification forming part of Letters Patent N0. 38,368, dated May 5, 1863 5 antedated May 3, 1863.

To all whom it may concern:

Be it known that I, BENJAMIN T. BABBITT,

`of the city, county, and State of New York,

, vertical section of the same.

Similar letters of reference indicate corresponding parts in the several figures.

This invention consists in the arrangement of one or more screw-propellers, each within a stationary cylindrical casing, in combination with peculiarly-constructed chambers in front and rear of such casings, whereby I am enabled to discharge at the stern ot' the vessel, by the action of the propeller or propel- 1ers, a column of water of an area equal to that of the greatest submerged section of the vessel and so to prevent any tendency to the formation of a vacuum asterp of the vessel, and the consequent retardation of its progress.

'Io enableI others skilled in the art to apply my invention tov use,` I will proceed to describe its construction and operation.

In carrying out my invention I propose to reduce the area of the transverse section of the vessel toward the stern, to give the stern as great an area of submerged section as any other part ot the vessel. v

The particular vessel represented is one of very lgreat breadth of beam and very light draft, intended as a floating-battery for harbor-defense, and owing to its great breadth of beam it is provided with a large number or screw-propellers, A A, as I propose in all cases that the propellers shall occupy the whole width, or as nearly as possible the whole width, of the stern. The separate stationary cylindrical casings G C, in which the several propellers are placed, are arranged side by side as close as practicable in a strong solid bulk-head, G, whichextends the whole width of the vessel, and which is united with the upper portion, E, and sides F F of the stern of the vessel, the said upper portion and sides being extended beyond the lower portion, B, of the stern, and the said bulk-head forming between it and the lower portion, B, of the stern a chamber, D, which is open at the bottom and which has a horizontal area equal to the aggregate area of the interiors of the several propeller-casin gs C C. The propellers may be of such diameter as to be entirely sub merged, but I prefer to make them somewhat larger, so that they will be submerged to about three-fourths or four fths of their diameter, to obtain an aggregate area of 'propelling-surface equal to the whole submerged section of the vessel. The upper portion and sides of the stern also extend beyond the bulk-head Gr, and the so extended upper portion has a downward dip to make it enter the water and combine with the sides F F to formV a chamber, H, in rearj ot' the propellers, in which, though the propellers may not be entirely submerged, all the water which passes through them may be collected to be discharged in one column below the surface of the body of water in rear of the vessel. The shafts I I of the propellers extend across the chamber G and through the portion B of the stern of the vessel, to be driven by engines of any suitable kind and arranged in any suitable manner.

The propellers applied in the manner and in combination with the construction` of the vessel above specied take the water from the chamber D and discharge it through the casings C Cinto the chamber H, orportion of the stern which is continued abaft ofthe bulkhead G, Where it is collected in a column having an area equal to the area of the submerged section of the vessel, the place of the water taken from the chamber D being constantly supplied by water entering the said chamber from below. y

I do not claim placing screw-propellers Within stationary cylindrical casings 5 but What I claim as my invention, and desire to secure by Letters Patent, is-

The combination, with one or more screwpropellers, of chambers D H, constructed, arranged, and proportioned substantially as herein speciiied, for the purpose set forth.

B. T. BABBIT'I.

Witnesses:

J. W. OooMBs, M. M. LIVINGSTON. 

